Indian Journal of Chemistry

Sect. A: Inorganic, Bio-inorganic, Physical, Theoretical & Analytical

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CODEN: ICACEC; ISSN: 0376-4710 (Print), 0975-0975 (Online)

 

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VOLUME 50A

NUMBER 2

February 2011

CONTENTS

Rapid Communication

 

137

 

On mercurous nitrite and a basic mercurous nitrate derivative

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Subhas Samanta, Sreebrata Goswami &
Animesh Chakravorty
*

 

 

 

 

Mercurous nitrite, when left in air with adhering mother liquor, is slowly converted to a basic mercurous nitrate (n = 2) belonging to the homologous family of general formula, Hg2{(OH)Hg2}n(NO3)n+2.

 

         

 

Papers

 

141

 

A novel molecular descriptor, TG index, for calculating the detonation properties of explosives

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lemi Türker* & Selçuk Gümüş

 

 

 

 

A novel molecular descriptor index (TG) has been defined for modeling and estimation of detonation parameters of explosives. The index is simple to calculate, unique for each molecule and is applicable to heteroatom containing species.

 

 

 

 

149

 

Synthesis, characterization and catalytic activity of SnAPO-5 in hydrogenation reaction

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Manickam Sasidharan & Asim Bhaumik*

 

 

 

 

Tin containing aluminophosphate molecular sieve, SnAPO-5, has been synthesized hydrothermally with Sn(II) and Sn(IV) salts as precursors. The material exhibits good hydrogenation activity for reduction of cyclohexanone to cyclohexanol under liquid-phase reaction conditions.

 

 

 

 

 

 

156

 

Influence of promoter and Fe2+/Fe3+ ratio on microstructure of fused iron catalysts for ammonia synthesis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Zhi-ying Pu, Yi-fan Zheng*, Hua-zhang Liu &
Xiao-nian Li

 

 

 

 

Addition of promoters and the Fe2+/Fe3+ ratio significantly influence the microstructure of fused iron catalyst. Catalysts with high Fe2+/Fe3+ ratio are superior in terms of promoter effects as well as pore distribution, leading to higher catalytic activity.

 

 

 

 

163

 

Photodegradation of carboxylic acids on Al2O3 and SiO2 nanoparticles

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C Karunakaran*, R Dhanalakshmi, G Manikandan & P Gomathisankar

 

 

 

 

Photonic efficiencies of Al2O3 and SiO2 nanoparticles are comparable to those of widely used nanosemiconductors, viz.,  TiO2 P25 Degussa, TiO2 Hombikat, TiO2 anatase, TiO2 rutile, ZnO, SnO2, and ZrO2. Photodegradation of carboxylic acids on Al2O3 and SiO2 nanoparticles increases linearly with acid concentration and photon flux.

 

 

 

Notes

 

171

 

Effect of an ancillary ligand on single helix-double helix interconversion in copper complexes. Copper(I)-water bond

 

 

 

 

 

 

 

 

 

 

 

 

Senjuti De, Shubhamoy Chowdhury,
Michael G B Drew & Dipankar Datta
*

 

 

 

 

A copper-water bond at the fifth position in a single helical copper(II) complex, which persists in the corresponding copper(I) species, blocks the pathways (ii)-(iv) usually observed in copper helicates.

 

 

 

 

176

 

Synthesis of nickel nanoparticles with fcc and hcp crystal structures

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K Joseph Antony Raj & B Viswanathan*

 

 

 

 

Calcination of nickel nanoparticles at 450 °C results in the sintering of nickel nanoparticles, thereby increasing the crystallite size. SEM image reveals that the particle size is in the range of
5–58 nm for fcc-Ni nanoparticles calcined at 450 °C for 10 min.

 

 

 

180

 

Heteroatom effect on intramolecular double proton transfer of 3,6-diiminocyclohexa-1,4-diene-1,4-diamine: A theoretical study

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hasan Tahermansouri*, Shahram Moradi & Robabeh Sayyadi

 

 

 

 

Intramolecular proton transfer in 3,6-diiminocyclohexa-1,4-diene-1,4-diamine and some hetero derivatives has been investigated at HF and DFT (B3LYP) levels of theory in both, concerted and stepwise, mechanisms.

 

 

 

 

Authors for correspondence are indicated by (*)

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 137-140

 

On mercurous nitrite and a basic mercurous nitrate derivative

Subhas Samanta, Sreebrata Goswami & Animesh Chakravorty*

Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India

Email: icac@iacs.res.in

Received 4 January 2011; accepted 18 January 2011

Mercurous nitrite, first reported by P C Ray in 1896, has a centrosymmetric structure with unsymmetrical nitrite chelation consistent with the hybridization of the metal-metal bond. When left in air with adhering mother liquor it is slowly transformed into a stable basic salt, Hg6(OH)2(NO3)4, having a centrosymmetric zigzag structure in which each of the OH group bridges two mercurous moieties and pairs of nitrate ions cap the terminal metal atoms. In both, relatively weak intermolecular Hg-O bonding is present in the lattice. The basic salt (n = 2) belongs to a homologous family of general formula Hg2{(OH)Hg2}n(NO3)n+2.

Keywords: Inorganic chemistry, Nitrites, Nitrates, Mercurous nitrite, Basic mercurous nitrate,
Crystal structure

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 141-148

 

A novel molecular descriptor, TG index, for calculating the
detonation properties of explosives

Lemi Türkera, * & Selçuk Gümüşb

aMiddle East Technical University, Department of Chemistry, 06531, Ankara, Turkey

bYuzuncu Yil University, Department of Chemistry, 65080, Kampus, Van, Turkey

Email: lturker@metu.edu.tr

Received 27 October 2010; revised and accepted 25 January 2011

A novel molecular descriptor index, viz., TG index, has been defined for modeling and estimation of detonation parameters of explosives. The index is simple to calculate, unique for each molecule and is applicable to the heteroatom containing species. The results of the correlation analyses of the TG index with the explosion data indicate that the TG index can be a very successful tool for prediction of the detonation parameters of explosives, within the limit of very small percent errors.

Keywords: Theoretical chemistry, Graph theory, Molecular descriptors, TG index, Detonation parameters, Explosives

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 149-155

 

Synthesis, characterization and catalytic activity of SnAPO-5 in hydrogenation reaction

Manickam Sasidharana & Asim Bhaumikb, *

aDepartment of Chemistry, Faculty of Science and Engineering, Saga University,
1 Honjo-machi, Saga 840-8502, Japan

bDepartment of Materials Science, Indian Association for the Cultivation of Science,
Jadavpur, Kolkata 700 032, India

Email: msab@iacs.res.in

Received 5 October 2010; revised and accepted 10 January 2011

Tin containing aluminophosphate molecular sieve with AFI structure (SnAPO-5) has been synthesized hydrothermally by using Sn(II) and Sn(IV) salts as precursors. The SnAPO-5 materials have been thoroughly characterized by powder X-ray diffraction, FTIR, UV-vis spectroscopy, scanning electron microscopy, thermal analysis, N2 sorption and surface area measurements, and elemental analysis using ICP. FTIR and UV-vis spectral data of calcined SnAPO-5 reveal that Sn can be substituted for the phosphorous sites up to 2 mole% in the framework lattices. Substitution of Sn preferably occurs at the phosphorous sites rather than for Al at lower metal concentration [Sn(II) or Sn(IV) ≤ 2 mole% SnO2] but higher loading leads to octahedral tin species. The calcined SnAPO-5 material exhibits good hydrogenation activity for the reduction of cyclohexanone to cyclohexanol using 2-butanol as hydrogen donor molecule under the liquid-phase reaction conditions. Other metallophosphates such as CoAPO-5, MnAPO-5 and FeAPO-5 fail to undergo this hydrogenation reaction under similar experimental conditions.

Keywords: Catalysis, Aluminophosphates, Tin, Molecular sieves, Metallophosphates, Hydrogenation, Cyclohexanone

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 156-162

 

Influence of promoter and Fe2+/Fe3+ ratio on microstructure of
fused iron catalysts for ammonia synthesis

Zhi-ying Pua, Yi-fan Zhenga, *, Hua-zhang Liub & Xiao-nian Lib

aResearch Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou 310014, PR China

Email: fxcszx@zjut.edu.cn

bCollege of Chemical Engineering and Materials Science, Zhejiang University of Technology,
Hangzhou 310014, PR China

Received 25 March 2010; revised and accepted 11 January 2011

Fused iron catalysts have been prepared by melting a mixture of magnetite powder, reducing agent (iron) and promoters (K, Ca and Al). The effects of the Fe2+/Fe3+ ratio and addition of promoters on the microstructure of the catalysts have been investigated by X-ray diffraction, high-resolution scanning electron microscopy and energy disperse spectroscopy techniques. The XRD results indicate that the addition of the promoters restrains the occurrence of disproportionation reaction and favors the formation of wustite. SEM and EDS measurements show that the Fe2+/Fe3+ ratio significantly influences the microstructure of the catalyst as well as the distribution of the promoters K and Ca. The catalyst with high Fe2+/Fe3+ ratio is reduced more easily than that with low Fe2+/Fe3+ ratio. The promoter in the sample with high Fe2+/Fe3+ ratio is distributed homogeneously on the surface of particles as needle-like films. After being reduced, the sample with low Fe2+/Fe3+ ratio has a compact structure with the promoter being distributing heterogeneous on the catalyst surface in an amorphous state, while the sample with high Fe2+/Fe3+ ratio had a porous structure and on the surface of particles the promoter is crystalline.

Keywords: Catalysts, Fused iron catalysts, X-ray diffraction, Iron, Ammonia

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 163-170

 

Photodegradation of carboxylic acids on Al2O3 and SiO2 nanoparticles

C Karunakaran*, R Dhanalakshmi, G Manikandan & P Gomathisankar

Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamilnadu, India

Email: karunakaranc@rediffmail.com

Received 7 October 2010; revised and accepted 27 January 2011

Al2O3 and SiO2 nanoparticles effect photodegradation of carboxylic acids, and their photonic efficiencies are comparable to those of TiO2 P25 Degussa, TiO2 Hombikat, TiO2 anatase, TiO2 rutile, ZnO, SnO2, and ZrO2 nanosemiconductors. All the nanoparticles show sustainable photoactivity and the degradation rates increase linearly with oxalic acid-concentration and photon flux. The photonic efficiencies of degradation are in the order: formic acid > oxalic acid > acetic acid > citric acid. The mechanism of photodegradation is discussed.

Keywords: Photochemistry, Catalysis, Photocatalysis, Photodegradation, Nanomaterials, Oxides, Semiconductors, Electrical properties, Alumina, Silica

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 171-175

 

Effect of an ancillary ligand on single helix-double helix interconversion in copper complexes. Copper(I)-water bond

Senjuti Dea, Shubhamoy Chowdhurya, Michael G B Drewb & Dipankar Dattaa, *

aDepartment of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India

Email: icdd@iacs.res.in

bSchool of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, UK

Received 22 September 2010, revised and accepted 10 January 2011

Reaction of Cu(ClO4)2.6H2O with the 1:2 condensate of benzildihydrazone and 2-acetylpyridine, in methanol in equimolar ratio yields a green compound which upon recrystallisation from 1:1 CH2Cl2-C6H6 mixture affords [CuL(H2O)](ClO4)2.½C6H6. The complex crystallises in the space group  P-1 with a = 8.028(11) Å, b = 12.316(17) Å, c = 18.14(3) Å, a = 97.191(10)o, b = 94.657(10)o and g = 108.039(10)o. It is single helical with the metal having a distorted trigonal bipyramidal N4O coordination sphere. The acid dissociation constant of the Cu(I) complex in CH3CN is 3.34 ± 0.19. The X band EPR spectrum of the compound is rhombic with g1 = 2.43, g2 = 2.10, g3 = 2.02 and A1 = 79.3 x 10-4 cm-1. The Cu(II/I) potential of the complex in CH2Cl2 at a glassy carbon electrode is 0.43 V vs SCE. It is argued that the copper-water bond persists in the corresponding copper(I) species. Its implications on the single helix-double helix interconversion in copper helicates are discussed. DFT calculations at the B3LYP/6-311G** level shows that the binding energy of water in the single helical five-coordinate copper(I) species [CuL(H2O)]+ is ~ 40 kJ mol-1.

Keywords: Coordination chemistry, copper, Helical compounds

 

 

Indian Journal of Chemistry

Vol. 50A, February 2011, pp. 176-179

 

Synthesis of nickel nanoparticles with fcc and hcp crystal structures

K Joseph Antony Raj & B Viswanathan*

National Centre for Catalysis Research, Indian Institute of Technology Madras, Chennai 600 036, India

Email: bvnathan@iitm.ac.in

Received 28 September 2010; revised and accepted

Nickel nanoparticles have been synthesized using nickel nitrate, vegetable oil and sucrose. Ethanol has been used as a solvent since the heat of reaction shows the destabilization of nickel particles if water is present in the synthesis mixture. Nickel with fcc phase is obtained by reduction with sucrose followed by stabilization using vegetable oil. Nickel or possibly nickel carbide with hcp structure is obtained by treatment with a mixture of oleylamine and methanol. The fcc and hcp crystal structures have been characterized by XRD. The calcination of nickel nanoparticles at 450 °C results in the sintering of nickel nanoparticles, thereby increasing the crystallite size. The scanning electron micrograph reveals that the particle size is in the range of 5 – 58 nm for fcc-Ni nanoparticles calcined at 450 °C for 10 min.

Keywords: Nanomaterials, Crystal structure, Nickel, Heat of reaction

 

Journal of Chemistry

Vol. 50A, February 2011, pp. 180-184

 

Heteroatom effect on intramolecular double proton transfer of 3,6-diiminocyclohexa-1,4-diene-1,4-diamine: A theoretical study

Hasan Tahermansouria, *, Shahram Moradib & Robabeh Sayyadic

aDepartment of Chemistry, Islamic Azad University, Ayatollah Amoli Branch, PO Box 678 Amol, Iran

Email: tahermansuri@yahoo.com

bDepartment of Chemistry, Islamic Azad University, Tehran North Branch,Tehran, Iran

cDepartment of Chemistry, Islamic Azad University, Rasht Branch, P. O. Box 41335-3516, Rasht , Iran

Email:sayyadi@iaurasht.ac.ir

Received 2 November 2010; revised and accepted 27 January 2011

The process of intramolecular proton transfer in 3,6-diiminocyclohexa-1,4-diene-1,4-diamine  and some hetero derivatives has been investigated at HF and DFT (B3LYP) levels of theory in two states, concerted and stepwise. In 3,6-diiminocyclohexa-1,4-diene-1,4-diamine, the energy barrier for the proton transfer through concerted and stepwise mechanism is found to be ~ 27 and 17 kcal/mol, respectively. When replacing two CH groups by two boron atoms in the ring (3,6-dihydro-3,6-diimino-1,4-diborinine-2,5-diamine), the obtained energy barriers are ~ 48 and 26 kcal/mol, respectively. The values obtained on replacing the CH groups by two atoms of nitrogen, silicon and phosphor are ~30 and 18 kcal/mol (3,6-dihydro-3,6-diiminopyrazine-2,5-diamine), 86 and 45 kcal/mol (3,6-dihydro-3,6-diimino-1,4-disiline-2,5-diamine) and 84 and 45 kcal/mol (3,6-dihydro-3,6-iimino-1,4-diphosphinine-2,5-iamine) respectively. The displacement pathway and the resonance forms that are produced in the conversion processes have been investigated. The nucleus-independent chemical shift methodology has been applied to study the charge distributions in the ring.

Keywords: Theoretical chemistry, Proton transfer, Heteroatom effect, Charge distribution, Chemical shift